Variables & Constants

The Storage Boxes

Think of computer memory as a warehouse full of boxes. A variable is a labelled box where you can store data - and change what's inside whenever you want. The label (name) stays the same, but contents can change: "score = 10" then later "score = 15". A constant is a sealed box - once you put something in, it can never change. Use constants for things like PI = 3.14159 or VAT_RATE = 0.20.